BRISOL谱仪关键技术研究

HI-13串列加速器升级工程在线同位素分离器（BRISOL）需对同质异位素进行分辨，谱仪设计质量分辨率为20 000，是很高的技术指标，对离子源、高压、分析磁铁、四极透镜等设备均有很大的挑战。本文详细介绍了BRISOL谱仪关键技术及其测试结果。能散对谱仪的质量分辨率影响较大，BRISOL谱仪设计采用异能大小铁结构消除能量色散。离子源采用表面离子源，并采用三电极引出系统，中间电极电压可调用以优化束流品质，优化后离子束RMS发射度好于3.8 πmm•mrad。分析磁铁采用表面线圈进行磁场垫补，垫补后积分场均匀性好于3.5×10^-5。为修正像差，大分析磁铁安装了β线圈和γ线圈，同时，在分析磁铁前后共设置了4台电六极透镜。

Research on Key Technology of BRISOL Separator

The mass resolution of Beijing Radioactive Ion Beam Facility Isotope Separa‐tor On‐Line (BRISOL) is designed of 20 000 for the separation of isobar beam .It is a great challenge for all the elements of the BRISOL facility ,including ion source ,high voltage , analysis magnets , quadrupoles , and so on . The key technologies of the BRISOL separator and the test results were introduced in this paper .To reach the high mass resolution of 20 000 ,a bi‐energy system was used to reduce energy dispersion which is too large to get high mass resolution .A surface ion source with three elec‐trodes extraction geometry was developed for the BRISOL facility .The RMS emittance of the beam can be optimized to 3.8 πmm · mrad by turning the voltage of the middle electrode .The surface coils were set on pole faces to improve the magnetic field homo‐geneity .The integral field uniformity with surface coil is optimized to 3.5 × 10-5 .Theβsurface coil and γ surface coil were fitted on the pole of big magnet and four electric hexapoles were also used to eliminate the aberration .